1. Field of the Invention
The present invention generally relates to printed circuit boards, and particularly, to a printed circuit board providing heat dissipation.
2. Discussion of the Related Art
Printed circuit boards (PCB) are commonly employed as a base or carrier for circuit elements such as microprocessor chips, power die transistors, semiconductors and other circuit components. Presently, many electronic assemblies require small volume, with the PCB requiring the same, such that circuit elements must be densely assembled thereon. As a result, heat produced by the circuit elements is accumulated on the PCB, presenting difficulty in the dissipation thereof. Thus, the circuit elements have an unduly short functional lifespan. Such PCBs generally incorporate a system for heat dissipation, such as a heat dissipation hole defined in the PCB, a metallic layer formed on the PCB, a metallic sheet attached to a rear portion of the PCB, or a layer of thermal grease.
A typical PCB includes an insulated sheet, copper foil formed on the sheet, and a solder mask partially coating the copper foil. Areas of the copper foil not coated with solder mask form a plurality of cross-shaped copper zones. When the PCB is placed into a tin stove, tin alloy is formed on the copper zones in corresponding cross-shaped tin strips, providing heat dissipation. However, the tin strips occupy a relatively large area, occupying valuable footprint space, and, in fact, if circuit elements need to be densely mounted on the PCB, there will be not enough room for formation of the tin strips. Accordingly, the tin strips offer only limited efficacious benefit.
Therefore, a printed circuit board providing heat dissipation is desired to overcome the described limitations.